Diamond girdling machine



Get. 26, 1943. w J HQPP DIAMOND GIRDLING MACHINE 5 Sheets-Sheet 1 Filed July 15, 1942 INVENTOR: WILLIAM J. HOPP Oct. 26, 1943. w. J. HOPP ,3

DIAMOND GIRDLING MACHINE Filed July 15, 1942 5 Sheets-Sheet 2 INVENTOR. WILL/A J. opp

ATTORNEY 00%. 26, 1943.. w 1 HIOPP DIAMOND GIRDLING MACHINE Filed July 15, 1942 5 Sheets-Sheet IS IN V ENT OR:

Uct 26, 19430 W. J. HOPP DIAMOND GIRDLING MACHINE Filed July 15, 1942 5 Sheets-Sheet 4 INVENTOR.

Patented Oct. 26, 1 943 DIAMOND GIRDLING MACHINE v William J. Hopp,j New York, N. Y.', assignor to I Harry Winston, Inc., NewvYork, N. Y., a corporation of New York Application-Jilly 1942, Serial No. 450,959

, 4 Claims.

My invention relates to diamond girdlingia step in the art of grinding diamonds 'by which step the lateral corners of the raw'stone are rounded and the stone, thereby is preparedfor faceting. Other precious stoneshavinga-hard- 5' ness and other physical-qualities similar to diamonds may be girdled in the same way. My'in vention relates also to such precious stones, and it is understood that speaking of diamonds, I include such similar stones. v 1

The girdling of diamonds is a process which must be handled very delicately for several reasons, especially in order to avoid scratches or. splitting whereby precious material would be lost. Sofar as I am aware, this operation has'been heretofore accomplished by highly skilled 'w'orkmen who have been holding a diamond'pasted on to a holding tool against the diamond tobe girdled; the diamond tobe girdled was held by a special paste on to a revolving holder. Even an experienced workman failed often 'to accomplish the desirable accuracy of the shape Or the largest" possible size of'theproduct. An object of my invention is to provide a ma: chine for the girdling of diamonds and airno'tor driven grinding wheel as a tool for cutting-the corners of the diamond to be girdled. Further ob je'ctsare to increase the economy of this operation, to reduce the time required for the same; to make the girdling process more accurateand less dependent on skilled labor, and to avoidnany loss of material and other drawbacks mentioned above. y Further objects are to provide a, machine hav ing ashaft rotatable at uniform speed, to provide in this machine means for holding a diamond so that the central axis of the stone coincides with the axis of said shaft, to connect said holding means to the shaft exchange'ably or adjustably, to provide means to exert an axial pressure on the stone whereby the diamond. is held and centered, the conventional cementing or. fusing of th'ej stonei is unnecessary and the diamond can be quickly" s'erted intoand removed from the machine; Still further objects are to provideaygrinding' wheel which is so situated and'shap'ed thatfthe; peripheral surface of said wheel can be usedto cut or to grind the cornersof the stonewhereby; that part ofthe' grinding Wheel acts as a tool' which moves at the highestspeed and a high. speed of the grindingsurface is obtained with a relatively low number of revolutions per minute and withacentrifugal stress which will be well within the tensile strength of a diamond bond grinding wheel; to provide means to move the 55 Other objects and advantages will the nature of the improvements is betterund en termgrinding wheel gradually and at any desired speedin a direction perpendicular to the axis of the stone carrying shaft whereby the progress of the girdling operation can be regulated as it {is best suitable; and to provide momma means for the rotation of both the stone carrying "shaft andthe grinding wheel, which means are mesmeent from each other whereby the means driving the grinding wheel may take part inthe hdri zonta l movements of the grinding wheel and said movements do not interfere with the respective motoric means. Y

The extreme hardness: ofthe stone and the relative weakness of the substance-binding the,

grinding wheel makes it dilficult-to avoidscratches in the grinding wheel because the diamond is apt to cut into the wheel if theacting line. of the grinding surface does not change perpetually.- Thereiore; another object isto' avoid this drawback and to provideiriea-ns to move the grinding wheel perpetually to and from a' direction parallel to the axisof the stone carryingshaft. In corrsaid-imotoric means independent from the other rhetoric means used in the machinefto provide means" toiftra-nsmit the oscillating drive from a stationary motor tothe grinding wheel whatever the position of said wheel to'the stone might be: andto provide exchangeable or adiustablemeaii's byfvvhich the distance and the frequency of the Oscillation n-P eso sel'eete zas it is desired a ai ticul"ar case. v n

Stillafurtherobject is to produce a machine of the-character described in which the maximumsimplicity of construction and-operation is 'se-' cured. v s l 1 appear as stood, the invention consisting substantially in thenbvel shape} arrangement and co-operation of parts' hereindescribed and illustrated in are accompanying drawings, wherein similar referencecharaoters' are used to indicate-correspond ing parts throughoutwhe several figuresland then finally pointed out and specifically defined in the appended claims.

The disclosure made the basis of exemplifying the present inventive concept suggest a practical embodiment thereof, but the invention is not to be restricted to the exact details of this disclosure, and the latter, therefore, is to be understood from an illustrative, rather than a restrictive standpciilt. n v

The in'venti'veidea involved is capable of re- Figure 1 shows a front elevation of the entire machine on a reduced scale, some parts being omitted for the sake of clearer representation.-

Figure 2 shows a cross-section taken along the line 22 in Figure l and seen from theright side, some parts being omitted.

Figure 3 shows a plan View of the machine tively.

'spectively, stand in line with the pulley II and I2 and drive the latter by means of rope or belts. In the shown embodiment, the diameters of the pulleys are so measured that the countershaft l4 makes about 200 revolutions and the shafts 6, 1"

about 400 revolutions per minute. The motor (3 and the brackets l1, iii are secured to the lower level of the ta ble I either-immediately or by means 'of' an interposed mounting plate; Openings areprovi'ded in the u'pper'levelof the table for the passage of the ropes connecting the pulleys H and I2 to the pulleys l9 and respec- The finished surface of the mounting plate 2 carries .a sliding frame 2| which is movable along twoslidingbaLrs ,22 permanently aflixed to the plate 21 The name 2| and the plate 2 are provided with openings for the passage of the rope or shown in Figures 1 and ,2, seen from above whereby ,the upper level of the machine is visi,- blea I I Figure 4 shows ahorizontalcross-section taken along the line 4 -4 inFigure land seen from above whereby the lower level of the machine'is visible. p e .Figure 5. shows the front and'the side view of the approximate typical form of a diamond before and afterthe, girdling, on an enlarged scale. Figure 6 shows a partlysectional horizontal ele.- Vation of details belonging to the stone carrying shaft, in about natural scale. I

Figure fl. shows a vertical side elevation of some parts shown in Fig. 6. e

, Figure 8 shows a partly sectionalside elevation of one of thestone holding members, on an enlarged scale. 7 v

Figures 9 and 10 show partly sectional side elevations of details belonging to the oscillating de vice on about natural scale, Figure 10 being the continuation of Figure,9 to the right side.

' 1 Figure 11 shows a plan view of details shown in Figures 9 and 10, someparts of said details being broken off. e v Referring to the drawings, numeral l indicates a table having two horizontal levels. A mount ing plate 2 having a finished upper surfacev is secured by screws to the upper side of, the upper level ofv said table. Said connecting screws and Qther.-,connections which will be referred" to in the following and may be carried out byconventional means in known manner are not shown in the,drawings. M e s The brackets 3.4, and 5, each of which has a boring at itsupper end, are so mounted .on'the plate 2 thatthe axes of their borings'fall into one line.- A shaft consisting ofa left section 6 and a right section. 'l-, is rotatably borne by said brackets as will be described later on. Between the sections 6 and l of the shaft,-there is-a disbelt connecting the pulleys l2 and 20. The frame 7 2| is further provided with an eye 23 (Figures 7 2 and 3) .having a threaded: boring. v A bolt-24 having a threaded end engaging-the thread of -th e eye 23 is rotatably carried by abearing 25 and secured'to. said bearing 'inexiaI direction. The bearing25 is permanently aifixed to the mounting' plate 2. A hand wheel, 261s connected with the bolt '2'; whereby turning of said hand wheel will move the sliding frame 2! in the direction of theboltsaxis.

A support plate 2'! is slidably superposed to the frame 2| and carries a bracket28which is permanently connected with the plate 21. p The entire machinery comprising 1 the plate 21, the bracket 28 and. the parts carried by said bracket is, by means which will be described later on, guided in the frame zl in a direction perpendicular to the direction in which the frame 2| is moved by the hand wheel 26. L

The bracket2 8 is provided with abearing 29 for a shaft carrying a diamond bond grinding wheel 30 which is so positioned that :the' sliding movement of the frame 2| varies the distance of the grinding circumferene of saidwheel from the stone held between the inner ends of the, shaft sections 6 and 1. On its ,upper side, the bracket 28 carries a motor 3| having, in the described embodirnent, /20 H. P. and driving the grinding wheel 30 by means of a pulley 32 mounted on the motor shaft, a pulley. 33 mounte d on the shaft of the wheel 30 and a belt connecting the pulleys 32 and 33 so that the grinding wheel makes. about .4500

tanoe sufficient for the insertion of the two stone holders 8 and 9 (Figs. 6 and 8) between' which the stone I 0 is held during the girdling operation. A pulley H is secured to theleft shaft section 6, and a similar pulley I2 is secured to the right section I. a motor :l3 -w hich, in the shown embodiment, has a capacity:of H. P. and a speed-of revolutions per minute drives a countersha'ft l l by means of a pulley 15 mounted on the motor shaft andapulley l6. mounted on the countershaft Hi. The countershaft i4 is supported by bearings provided in borings of the brackets I1 revolutions per minute.

A motor 34 having, in the described embodi-T ment, l-I. P. and provided with-aratiomotor having an outputof 45 revolutions per minute is ported by bearings'in a bracket'38lmounted on the plate 2 and carriesj'also another sprocket.

(Figure 2) which is connectedbyalchain with a sprocket .40 on a shaft. 41.. The'shaft'jdl runs'in bearings provided in a bracket 42 whichis'also mounted on' tlie plate .2. The-.la tterhs'fhaft,fur;

ther, carriesa wheel .43 having a circumference provided withfcurved recesses (Figurev ll)..' -The transmission by h'ieans o'fi' tliej'sprockets ji, 3,6, 39- and 40 reduces-the speedfsfo, 'thatithe wheel-4 3 makes about '4 revolutionspe'r minutef f .[Thesuppo'rt plate 27 has anexte'hsien its right side (Figures v 9 andjlll, said -extension forming an. eye linked with a jointj to the legend: of a tarts (Figures 10 and 11 thegright end of. which is drawn to the right'side by a smash; O eneio th asn i a. .511 ai zi si' Wine-he the other end'toa stationary part, forexample, to the bracket 38'. r The bar 45 furthercarriesa small roller which is rotatable. around a pin affixed tosaid bar; .The roller 41 engages the circumference of. the wheel. 43wherebyithe bar 45 and .the support :plate .21. are movedto and fro when the Wheel 43 rotates, the spring 45 always securing close touch between the roller 41- and thewheel 43: f

Astud 48 (Figures 9 and 1-1) is secured to the lower side of the bracket 28 and extends downward through a hole 49 in. the support. plate 21 and through a slotted hole 50 in the sliding frame 2| .1 The lower'end. of' the stud 48 isequipped with a washer.5.l surroundingsaidend and. with a nut 52 engaging a threadon the stud. The mounting plate ,2 has an opening or recess pros vidingspace for thelower end of the stud 43. the nut 52 and the washer, 5|. Said .Washer. is pressed by the nut. 52, against. a .sholder onv the stud 48; so that tightening of the nutwill'not clamp the frame 2|. andthe plate 1''! together.

The stud 48 has amiddle portionof. a diameter larger than the diameters of the threaded ends. This middle portion is flattened down to a thick? ness slightly smaller than the width of the slotted hole 50 whereby said middle portiongobtains two parallel even surfaces, 53 and, slidably. fits .the side walls of the hole 50..

When the bar 45and the plate 21 oscillate, due to the rotation of the wheel 43, the bracket 28 will also oscillate and is guided in this oscillating motion bythe stud 48 sliding in the slotted hole 50. i The grinding wheel 30 carried by the bracket 28 takes part in, the oscillation and, thereby, moves to and fro in the direction of the slotted hole 50 whichis parallel to the-shafts 6, 7. The way or elongation of the oscillating movement .is' given by the d-epthof the'recesses-onthe circumference of the wheel .43 and is relatively small, at any rate smaller or not substantially larger than the thickness of the grinding wheel 30. The frequency of the oscillations depends on the speed and on the number of recesses of the wheel 43 and is, in the shown 48 per minute. i I I The boring of the brackett (Figures ,1, 2 and 3.) contains ball bearings. (not shown) similar to ball bearings 55 in the bracket 4 (Figure 6 The shaft'section -6 is inserted in said first ball bearings and has a slightly tapered boring in its embodiment, about right end for the insertion of a holder 8. A

similar boring is provided in the corresponding left end of the shaft section 1 forthe insertion of a similar holder 9' (Figure' il.

Usually, the diamon, Hi to be girdled, has the form of a regular four sided pyramid (Figure 5) this form being typical for the natural shape of the raw stones. four corners of the pyramids base are cut off and rounded as indicated by the dotted line in the left View of Figure 5. The line perpendicu-.

lar to the base surface and through the pyramids point is regarded as the axis of the stone, and the latter is so inserted in the machine that the axis of the stone falls into the axis of the shafts 6, I. As said before, the stone is held in this position by two holders 8 and 9 inserted into borings of the shaft sections 6 and 1. The stone holding ends of said holders are provided with cavities or recesses which may have any shape suitable for gripping the stone, for example, cupshaped or conical as shown in Figure 8. Several different types of holders which fit different sizes or shapes of stones may be kept in store. From these, that pair. of holders is selected which is mostsuitable in aparticular case. After the insertionof the holders, they are caused to grip the stone by a slight axial movement which will be described later on. I A

[The boring of the bracket 4 (Figures 6 and '7) contains a sleeve 54 'slidablein said boring. Two ball bearings 55 inserted in the'sleeve 54 support theshaft section l so that said section together with the bearings 55 and the sleeve 54 can slide in axial direction. The bracket 4 is provided with two eyes 55in which bolts'5l are secured; the outerends of which-are provided withthreads and nuts 58.- A sliding plate 59 is positioned on the left side of 'the sleeve 54 and provided with a centralhole for the passage of the shaft 1, with two lateral holes for the passage of the bolts 51 and withla rectan-gularly bent extension 60 forming an eye for a joint where :an arm 61 is 'linked. The arm 6| extends about parallel to the shaft axis and has a handle 62 and an incision or recess fitting the. pin 83 which is secured to the side of. the bracket 4. In the utmost right position (shown in dotted lines in Figure 7), saiclrecess is slipped over the pin 63 whereby the arm 6| is temporarily secured and holds the sliding plate 59 in its right end position. When the arm 6| is lifted by the handle G2,,the'pin $3 releases the arm, and the plate 59 is free to return to its utmost left position, excessivemotionbeing barred by the nuts 58.

The boringof the bracket 5 (Figure 6) con tains a sleeve :64 secured to said bracketv by a screw 65 and having a central boring in which a cylindrical body or piston 66 is slidablyv in-. serted. The piston 66 is pressed to the left side by a coiled spring 61 placed in the boring of the sleeve 64 and can be drawn to the rightside against the pressure of the spring 6.! by a hand boss 68 which is connected to the piston 66 by a central rod ,69- and guided in its axial motion by a thin pin l9 secured to the boss 58 and sliding in asmall hole of the sleeve 64.

On its outer side, the piston 66 terminates in a curved-reduced end ll fitting the inner side of balls l2 forming a ball bearing, the rotating ring of which forms a part of or is secured to the shaft section 1. Under the pressure of the spring 6?, the piston to presses the shaft section I to the left side toa position Where further axial motion is stopped, either by the plate 59 placed before the sleeve 54 or by the stone l0 held by the shaft section 6.

By the girdling operation, the

When the machine-is prepared for operation, such sizes of pulleys and sprockets may be selected from a store as will accomplish that ratio of the respective drives which is regarded as best fit for a particular case, Also grinding wheels of different diameters, thicknesses, compositions or other properties may be kept in store for proper selection. It is of particular importance that several wheels of the kind of Wheel 43 are available, said wheels differing in number or depth of the recesses. Also these wheels may have different diameters. A set of rollers 47 may be kept in store, said rollers having different diamcarrying' shaft is facilitated by, the hand-boss, 68 which may be pulled to the right side in order. to release the right end of the shaft sectionftem porarily. The screw connection securing the bracket 28 to thesupport plate 2'! may provide fora slight adjustment of said parts in horizontal direction whenever such adjustmentis desired, for. example, to bring the grinding wheel;into thecorrect position with respect to the stone. q.

When the exchangeable parts have been selected and inserted andthe machine has been adjusted as said above, it is' ready for girdling a series of diamonds having about the same size. When a diamond is to be inserted, the workman pulls the handle 62, thereby opening the gap between the inner ends of the holders 8 and 9, holds the diamond between saidends and releases the handle again, whereuponthe stone 1S2 fixed in the operating position. Renewed operation of the handle 62 will release the stone again,v and then, the machine is immediately ready for the reception of the next stone.

After the diamond is inserted and the three motors are switched on, the Workman turns the hand wheel 26,. thereby gradually moving the grinding wheel 30 toward the stone until the cylindrical circumference of the grinding wheel contacts the diamond. Then he continues in this operation until the desired part of the stone is ground off. The gradual turning of the hand wheel 26 is the only operation which the workman has to perform during the grinding process. Therefore, he can concentrate his mind on this operation and accomplish a highly qualified result with little skill.

Every motor used in'the machine, also the motor 3| carried by the movable bracket 28, is stationary with respect to the shafts driven by the motor'whereby the drive is reliable and uniform during the entire grinding process and an accurate and uniform operation is secured.

The oscillation of the grinding wheel brings a broad band of its circumference in alternative contact with the diamond whereby a uniform consumption and long duration of the grinding surface and an accurate and economic grinding process is obtained. v

Having, thus described an illustrative embodiment of my invention and how it operates, I claim:

1. A diamond girdling machine having a shaft; means supporting said shaft; means for' turning said shaft; means for holding a diamond, said latter means connected to said shaft; a second shaft; motoric means for turning said second shaft; a grinding wheel affixed to saidsecond shaft; a bracket supporting said second shaft and carrying said motoric means for turning said second shaft; and means to oscillate said bracket,

2,332,574 I saidoscillating means comprising "af'wheelhavin recesseson itsv circumference; motoricvm'eans to turnsaid'wheehfabar-connected to said bracket andzextending inradial direction .to'said wheel; means connected'to said bar :and touching :the

circumference of said'wheel; and means to draw; I saiclzloar. as far inthe direction tosaidiwheel as Y the. present position 'of-said recesses" allows} 2. A diamond girdling machine having'a shaft; means supporting. said shaft; means for; turning said shaft means for holding j a diamond' said latter 'means connected to said shaft; asecond 1 shaft; ImOtoric meanS for turning said second shaft; a grinding wheel aifixed 'to' s aid- -scond shaft; a bracket supporting said 'secondi shaft and carrying said motoric means for turning said second shaft; and means to oscillate said bracket} I said oscillating means comprising a wheel liaving recesses on its circumference; motoric means for turnin said wheel; abarconn'ected to saidbra'cka' et; means connected to' said bar 'and contacting the circumference of said wheelc and -a' spring havingone end stationarily secured and the otheij' I end aflixed to said bar whereby saidspringtends to move-"said bar in thevdirectiontoward said WheeL' 'I 3. A diamond girdling-machinelhavinga shaft; means supporting said shaftyfmeans for turning said shaft; means for holding --'a diamond said latter means connected to said shaft; asecond shaft; motoric means for t'urnirig'said second shaft; a grindin wheelaifixed to [said second] shaft; 'a bracket supporting said second shaft and carrying said motoric-means for turning said second shaft; and means to oscillate said bracket'; a sliding frame carrying said bracke'tj means' toj guide and to move said' framel in a direction perpendicular to said first shaft; a' member con;

nected to'said bracket;- and mea'n's to' 'gui'd said:

member relative to said frame in a direction parallel to said first shaft.

4. A diamond girdling machine having a sha'ft; means supporting said shaft; means for turning said shaft; means for holdinga diamond -said latter meansconnected to said shaft; a-second shaft; motoric means forturningsaid' s'econ'd shaft; a grinding wheela'flix'ed to said'second shaft; a bracket supporting'said second shaft'and carrying said motoric means for turning said second shaft {and means to oscillate said bracket, said oscillating me'anscomprisirig a bar; a jo t connecting said barwith'said bracket; meansfto oscillate said'bar in longitudinal direction; said machine further comprising; a sliding frame car? rying said bracket; means to guide" and tomove said frame in a direction perpendicular to said first shaft; am'embfe'r connectedto said bracket;

and mean to guide said member relativeto said frame in a direction parallel to said' first shaft! 

